The present invention relates to a coupling mechanism for a headrest of a vehicle seat, and more particularly to a coupling mechanism for moving the headrest forward when a forward external force acts on a car body as a result of rear end collisions or the like.
Conventionally, there is known from Japanese Patent Application Laid-Open No. 10-119619 a vehicle seat having a headrest provided in a backrest, a movable member provided inside of the backrest, and a coupling mechanism for coupling the headrest and the movable member mechanically, in which, when a vehicle seat occupant moves backward relative to the vehicle seat due to rear collisions or the like, the movable member is pushed by the occupant to move backward, and the backward movement of the movable member moves the headrest forward by way of the coupling mechanism.
The coupling mechanism of the prior art is disposed substantially at the backside of a cushion of the backrest, and thus the cushion performance may be lowered. That is, the coupling mechanism is provided at a position overlapping the vehicle seat occupant in the front-to-back direction, and thus the cushion design is restricted.
The movable member in the prior art is narrow in its movable range, and the distance of moving the headrest forward is short, and means for compensating for lack of distance is difficult.